1. Field of the Invention
The present invention relates to an acceleration-sensing system and particularly relates to an acceleration-sensing system for sensing acceleration in a three-dimensional manner.
2. Description of the Related Art
Recently, various input techniques are required in technical fields such as the field of computer games. There is a particularly strong demand for techniques of inputting information related to human movements by sensing acceleration acting on an input device.
FIGS. 1A through 1D are diagrams used for explaining input techniques that are required in the field of computer games.
As shown in FIG. 1A, three-dimensional (3D) acceleration sensors 1 are attached to wrists and ankles of a game player. A game machine can detect the player""s movements by detecting movements of the wrists and ankles of the player from signals produced by the 3D acceleration sensors 1.
Accordingly, for computer game applications, for example, movements of a dancing player can be detected as shown in FIG. 1B, movements made by the player in a baseball game can be detected as shown in FIG. 1C and movements made by the player in a boxing game can be detected as shown in FIG. 1D.
In the related art, one-dimensional (1D) acceleration sensors for sensing acceleration in a one-dimensional manner and two-dimensional (2D) acceleration sensors for sensing acceleration in a two-dimensional manner are known. However, such 1D and 2D acceleration sensors are not suitable for detecting movements of the wrists and ankles that move in a three-dimensional space.
Known three-dimensional acceleration sensors mainly use piezoelectric elements and are not suitable for sensing accelerations of a relatively low frequency such as movements of a human body.
Accordingly, it is a general object of the present invention to provide an acceleration-sensing system that can obviate the problems described above.
It is another and more specific object of the present invention to provide a three-dimensional acceleration-sensing system that can detect acceleration of a low frequency such as movements of a human body.
According to the present invention, an acceleration-sensing system for sensing acceleration in a three-dimensional manner is provided which includes a first acceleration-sensing unit for sensing acceleration in a two-dimensional manner along first and second directions that are perpendicular to each other and a second acceleration-sensing unit for sensing acceleration in a one-dimensional manner along at least another direction that is perpendicular to the first and second directions.
With the invention described above, a mechanism for moving a magnet in the three-dimensional directions can be dispensed with. Therefore, the present invention is advantageous in that detection acceleration in the three dimensional directions can be achieved at a low cost. Further, the present invention is advantageous in that acceleration of a low frequency can be detected.
According to the present invention, the first and second acceleration-sensing units are mounted on the same circuit board. Therefore, the acceleration-sensing system can be provided with a reduced size.
According to the present invention, the electromagnetic conversion elements are mounted on the circuit board. Therefore, the circuit can be provided with a simple wiring pattern at a low cost.
According to the present invention, the structure of the first and the second acceleration-sensing units may be the same. Therefore, a reduced number of components are required for the acceleration-sensing system of the present invention and thus the acceleration-sensing system of the present invention can be constructed at a low cost.
According to the present invention, acceleration in the three-dimensional directions is detected by combining a plurality of acceleration-sensing units. Therefore, there is no need to provide a mechanism for moving a magnet in the three-dimensional directions. Therefore, the present invention is advantageous in that detecting acceleration in the three dimensional directions can be achieved at a low cost. Further, the present invention is advantageous in that low frequency acceleration can be detected.
According to the present invention, a plurality of acceleration-sensing units are attached to a single supporting member, which may be a hemispherical body. With such an acceleration-sensing system, a twisting movement can be detected.